CP2020 Rat Swarm

I recently watched a couple of Jeff Rients' videos about his "Broodmother Skyfortress" adventure he is developing.  He makes some interesting comments about the Giants not working according to standard monster mechanics.  The justification he gives for this is that the Giants are just too big for your characters' puny weapons to effect them in most cases.  This intrigued me.  For one, it makes the giants much scarier for the players, and it also sounds interesting in that it will force players to think out-of-the-box in dealing with them.  Anyway, here's my own humble monster along those lines.

The Rat Swarm

The characters see more and more rats and finally find themselves in the midst of an obscenely large lair of malvolent rats.  The rats will eventually get up the confidence to swarm the party.  They will generally try to surround and cut-off the party.  They can run as fast as a person, but will not follow the party outside of their territory.

Swarm Advancement

Each round the swarm advances.  Assuming the rats are only coming from one direction, they will begin with the first rank of characters and will not advance to the inner ranks until they have killed-off the first rank.  The steps of advancement are:

1. Legs Covered
2. Torso Covered
3. Arms Covered
4. Head Covered

 A character can spend their turn knocking the swarm off a particular limb of their own or of a party member.

Swarm Damage

If the swarm covers a body area, they will have the following effect:

• Bare skin or thin cloth: 1d6 bite damage to limb.
• Soft armor(leather, cloth, kevlar): 1d6 bite damage to limb.  Any damage blocked by armor SP is permanently subtracted from armor's SP due to chewing through the armor.
• Hard Armor(metal, stone): no effect.

Scaring the Swarm

The party can keep the swarm from advancing during a particular round by scaring them.  They will have to make a cool check which, if they fail, means that they do not advance on their next turn.  The check is rolled as a 5+1d10.  For example:

• character shoots 1 or 2 bullets into the swarm.  Cool check requires 5 or higher.
• character shoots full-auto into the swarm.  Cool check requires 10 or higher.
• character throws grenade into swarm.  Cool check requires 15 or higher.

If the swarm critically misses this check(roll of natural 1) they will withdraw, shadowing the party and waiting for their chance to renew their attack.

Swarm Treasure

If the party does manage to defeat the swarm, either by coming in full-metal armor(by coming with a flamethrower and lots of fuel, etc.) they will find the metal/stone possessions of 2d20 other victims.  They will also find the source of the freakish rat-swarm(pick one):

• Radioactive waste
• Dimentional portal
• Ancient pagan altar
• The Broodmother
• Strange glowing metiorite
• Remains of genetic lab
• ...